Riddle



V. J. DAVIS Jan. 8, 1935.

RIDDLE Filed Dec. 7, 1929 ZSheetS -Sheet 1 mm L gwvomtoz Y/errzon J gal/17$ Jan. 8, 1935. v. J. DAVIS 1,987,001

RIDDLE Filed Dec. 7, 1929 2 Sheets-Sheet 2 $511 afd yaw abtmweqs Patented Jan. 8, 1935 UN TED. STATES;

PATENT!" OFFICE 7 Claims.

This invention relates to improvements in riddles of the kind which-,- although available for other purposes; have-characteristics which render them particularly desirable in connection with sandscreening operations. A-riddleofthis type consists generally of a' screen bearing frame which is operatiVeIy cQnnected for vibratory movements to a suitable-motorand an auxiliarymechanism which co-operateswith the actuating'mechanism'in the support of the frame, the auxiliarymechanism, being designed'to permit thevibratory movements of "the said frame which are effected through the agency of the motor;

One object of 'the present invention is' to provide an auxiliarysupporting mechanism of the type generallydescribed" which, while-- capable of permitting relatively high speed vibration of the frame; is quiet in operation and) in which wearingof the parts is -minimized, therebyenabling its use over long'periods without the'necessity' of "adjustment or replacement of parts.

' A furthenobject is an auxiliary supporting mechanism. which is adjustable thereby facilitating. rapid assembly of" the parts as well as-enabling 'compensati on'for wear;

the type in which theoperating' and supporting mechanisms are located wholly beyond one end" of the riddle, thereby enablinguse of the riddle in a limited space as, for. example, between'the discharge endof a sand hopperand a chain. of molds therebeneath,.it being advantageous in order to save time and labor to screen the sandduring its passage from the sand hopper to'the' molds.

A further object is toprovide an improved ac tuating mechanismbywhich the screen is subjected to relatively. high speed vibrations of a rel.-

atively short throw best adaptedto the passage of. a. maximum quantity of material through. the

riddle in agiven periodof time.

A.stillfurther object is to provide an improved screen so-constructedas to .insure a substantially uniform. distribution of the sand ,or material therein over the greater portion. of the screeningisurface during the. vibratory movements of the riddle,- this. object contemplating. the provisionof. a. series of corrugationspresenting inclined faces .to the normaloutwardjfiowof the material andv tending to. .counteract I such flow.

Theinvention. is illustrated. in the accompanying .drawings in which;

Figure 1 is a side elevationof the riddle and.

(GIL 209"-326) Figure- 4 is a section-along line-"44,of Figure 2 with the motor in elevation.

F-igure5 isa'section along 1ine55 of Figure 2'. Figure 5 is a section along line6 6 of Figure 5; Figure 7 is- 'asection along line 7-7 of Figure 5 The-invention is illustrated in connection with a-riddle-ofthe type described in'my Patent/No. 1,728,335 of September 17,1929, inwhich'the op;- erating and supporting mechanisms for p the screen bearing frame are located whollybeyond one end-of the frame. It'is to be understood,hoW-

ever,; that insofar as the auxiliary'supporting,

mechanism herein" described and 'claimed' is com cerned-the invention is not dependent upon the location or'construction of the operating andsup'-' portingj'mechanisms, the riddle shown and'ide scribed being solely for the purpose of'illustra'e ion.

The screen-box- 1, as'illustrated, is supported for vibratorymovement by a horizontal'unit'2" .whichis carried byya suitable support, the-vi.- brating unit and support 1 therefor extending? wholly beyond one end of the screen box. The

support is preferably mountedfor swinging'move; v I V ment ina horizontal planetoipermitthe riddl'ef Afurther object is toprovide an'improved' construction of screen bearing unit'for'a riddle ofto "be swung to one side; whennot inuse. It irrcludes *a fixed bracket 3and a: swinging j member 4, the two said'parts being pivotallyconnectedj by a pivot pin 5; The swin'gingmember: 4'jis adapted'to carry the riddle supportigjandjactuat ing mechanism and, as illustrated, is beam-like in form. It is providedatitsouter' endwithla vertical supporting plateifi. to whichiissecured; as

to the arms li'to vibrate the unit. For this pur.--.

pose, the. shaft is extended. at. eachv end. at 9, whichextensionscarry. balance. wheels. 10. fixedthereto. The hubs ofthe balance whe'els are fashionedto provide'eccentrics 12- Which are. journalled in suitable ball bearings 13" mounted in openings-14a formed inthe arms 14'. Thesaid. openings 14a co-operate withsuitable plates15. and 16 to delimit. lubricating chambers which. maybe sealed-by suitable packing 1 5a .a'nd within.- which the ball bearings.13.are housed.

The inner end of the vibrating. unit. is con-J, nectedto theswinging member 4,to.permit.the. movement of the unit in the manner described. The'web portion of the member is, therefore, cut away toprovide an opening 41; in which thesaid" end is supported, the opening; ofcourse, being largeenough to p'ermit'the-vibratory movement tively. A disc 19 is seated in the lower recess 1391 and a disc is adjustably seated in the recess" 17a. The disc 19 is preferably resiliently seated' and for this purpose any suitable means may be employed, such means being illustrated as comprising a resilient disc 20d of rubber or the like which normally urges the disc 19 upwardly to maintain engaging co-operation between the supportingelements-of the inner end of the vibrating unit at all times during its operation whether the unit --be in'its extreme outward position or whetherin a position intermediate its extreme outwardand inward positions.

. A fulcrum -21is adapted to support the pivoted end oflthe unit and is mounted in a recess in the disc 19 or maybe integraltherewith. In-substantially vertical alignment with the fulcrum 21 are upper and lower bushings 23 and 24 which are preferably removably clamped between the inner ends of the angular extending arms 14 of thejvibrating unit. Asbest illustrated in Fig. 5, the upper bushing 23 is provided with a fulcrum 25 similar to the fulcrum 21 in the lower disc while-the lower bushing 24 has a V-shaped recess 26 sirnilartov the recess .22 inthe upper disc 20.

Two similar elements 27 and 28,'each having its upper pointed end positioned in a companion recess and its lower inverted V-shaped end seated u'pona companion fulcrum are adapted to suitably space the inner end of the unit in the opening 4a, the recesses ,co-operating with the upper ends of the spacing elements to prevent lateral movement of the same, it being understood, of course, that the vibrating movement of the unit effected by the eccentrics on the motor shaft is not sufficient to dislodge the elements from the said recesses and that the elementsare maintained in assembled co-operative relation by the connection ofthe vibrating unit with the motor.

In order to compensate for wear and to permit substitution of new parts for worn ones, the upper disc 20 is adapted to be adjusted vertically inthe recess 17. An adjusting screw. 12011 is,

" therefore, provided in the-upper boss 1'7 which may be rotated tofincrease or decrease, to the desiredextent, the pressure under which'the supportingielements 2'7 and 28 function.

- From the foregoing it will be apparentthat the screen bearing unit is partially supported by the actuating mechanism whichincludes the motor '7 and partially by "the elements 2'7 and 28.

- For .conveniencefthe,mechanism which includes auxiliary supporting mechanism.

these twov elements has been referred to as the In the embodiment of the invention illustrated the greater part of the load is carried by the actuating mechanism@ The term auxiliary, however, is not necessarily'intended to indicate that the auxiliary supporting mechanism carries a smaller part'of the load thanthe actuating mechanism. It will be'understood, of course, that this will not be the case in thoseinstances where the auxiliary supporting mechanism is employed in connection'with a riddle in which the actuating mechanism may be supported upon the opposite side of the screen box from that illustrated.

,During vibratory movements of the unit 2 the screen box 1 is movedthrough a substantially elliptic path. Lengthwise movement of the unit 2 during such vibration is relatively small and this results in slight rocking movements of the elements 27 and 28. The elements are so formed at their ends that-their engagement with the members 19 and 20 carriedby the swinging-member 4 as well as their engagement with the bush-' ,ings 23 and 24 carried by the unit 2 is effected through the agency of knife edges. construction has the advantage that wearing of Such a The balance wheels 10 may be counterbalanced 'as at 10a in order to relieve the shaft 8 from strain during the screening operation. It will be noted that the overbalanced portion of the;

wheel is diametrically opposite the thickest portion of the eccentricformed upon the hub extension. Byvirtue of this arrangement, the overbalanced portion of' the wheel is always at the top when the vibrating unit and screen carried thereby are in their lowest vertical position and vice versa,-whereby the said balance wheel always tends to counteract the actionof the vibrating unit upon the motor shaft,

The screen box 1,. as statedis vibration between the arms 14. carries trunnions 30 whichare journalled in bearings 31 said arms.

supported for Rubberbushings'iioa may be utilized to insure a-tight fit between the parts of the. bearing assembly-and to prevent rattling of the.

said parts during'thevibra'tion of the box. The box is maintained againstrotation' in a normally horizontal position by' laterally extending .lugs 32 carriedby the .arms 14 and a latch 33,the said lugs engagingthe rear low er corners of the screen box andthe latch 33 extending over and engagin'g'the upper edge of theback of the screen box intermediate its sides. The latch 33 is illus-j trated in its' normal operative position in which it extends over the-upper edge of the screen box as describe'dlbut it may be withdrawn by operating the handle 33a which is pivotally mounted,

in a housing 34. The housing 34 is supported inco-operative relation with respect to the screen box by a transverse tie-bar 35which is secured atits oppositeends to the arms 14 and cut away as at 35a ,(Fig. 3). to permitthe vibratory movement of the unit 2, the motor, of course, being stationary during this movement. In addition to' p'royidinga support for the latch housingthe bar 35 .also functions as a brace to keep the arms 34' properly spaced. When it is desired to clean It, therefore,

providedat the outer ends off the the screen the latch 33 may be withdrawn into I the housing 34 in the manner described and the screen box" rotated in a clockwise direction to an upside down position. When the accumulated matter. has been discharged the screen is returned to its originalposition by rotating it in an anticlockwise direction until the rear lower corners of the screen, box engage thelugs 32 at which time the handle 33a maybe released to permit the latch 33 to be extendedoverthe upper edge of the back of the screen box.

It will be observed that during the operation of the actuating mechanism, the motor shaft rotating in the direction of the arrowiFig. 3 the outer end of the unit and the riddle carried thereby are vibrated in a substantially elliptical path. Inasmuch as the spacing elements 27 and 28 maintain the inner end of the vibrating unit in substantially the same horizontal plane during this movement of the outer end of the unit, the riddle will be progressively canted in fore and aft directions during its opposite vertical vibrations. These vertical movements of the riddle in its path of vibration are more rapid than the fall of the sand. Consequently the screening fabric will strike the sand with such force as to tend to break the lumps and cause them to rebound, this action being aided by the canting of the riddle as described. The canting action of the riddle also aids in obtaining a fore and aft shifting of the mass of sand relatively to the. screening fabric so as to secure rapid and efiective screening results.

During the vibratory movements of the screen the sand or other material therein normally tends to move toward the forward end of the screen and accumulates there while the rear portion of the screen is utilized only to a small extent. In order to obtain a substantially uniform distribution of the material over the screening surface the screen is preferably formed with a series of transverse corrugations presenting inclined faces 36 toward the outwardly moving material, the extent of inclination of such faces being sufficient to counteract the normal tendency of the material to move to the outer end of the screen.

It is apparent from the foregoing that the screen may be operated and supported by mechanism located wholly beyond one end thereof if desired and that the space above and below said screen in this case is entirely unobstructed thereby per- .mitting the screen to be moved to a position between a hopper and a chain of molds without being obstructed by any part ofthe said hopper or molds and in such position rapidly vibrated for the purpose of screening the sand as it is delivered from the hopper and in the course of its passage to the molds.

Having fully described my invention, I claim:

1. In a riddle the combination of a screenbearing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it and mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed, inflexible, independently movable spacing elements which engage opposite sides of said unit at said end, said elements preventing movement of said end in a direction transverse of the length of said unit while permitting lengthwise and piv'- otal movements of said end.

2. In a riddle the combination of a screenbearing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it and mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed independently movable spacing bars which engage opposite sides of said unit at said end, said bars preventing movement of said end in a direction transverse of the length of said unit while permitting lengthwise and pivotal movements of said end.

3. In a riddle the combination of a screenbearing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it and mechanism for conof its length while permitting lengthwise and pivotal movements of said end.

4. In a riddle the combination of a screen-bearing unit, a motor, a support for said motor, ec- V centrics carried by the shaft of said motor which are journaled in said unit, whereby said unit may be vibrated by said motor and mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed, inflexible,independentlymovablespacingelements which engage opposite sides of said unit at saidend, said elements preventing movement of said end in a direction transverse of the length of said unit while permitting lengthwise and pivotal movements of said end.

5. In a riddle the combination of a screenbearing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it, mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed, inflexible, independently movable spacing elements which engage opposite sides of said unit at said end, said elements preventing movement of saidend in a direction transverse of the length of said unit while permitting lengthwise and pivotal movements of said end and means carried by said support for cooperating with one of said elements, said means being adjustable to maintain the desired adjustment of said elements.

. 6. In a riddle the combination of a screen-bearing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it, mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed, independently movable spacing bars which engage opposite sides of said unit at said end, said bars preventing movement of said end in a direction transverse of the length of said unit while permitting lengthwise and pivotal movements of said end, a mem ber carried by said unit and against which one of said bars bears and means for resiliently supporting said member.

7. In a riddle the combination of a screen-bear ing unit, a motor, a support for said motor, means for operatively connecting the motor to said unit for vibrating it, mechanism for connecting one end of said unit to said support, said mechanism being adapted to permit vibration of said unit by said motor and including opposed, independently movable spacing bars which engage opposite sides of said unit at said end, said bars preventing movement of said end in a direction transverse of the length of said unit while permitting lengthwise and pivotal movements of said end, members carried by said support against which the said bars bear, means for resiliently mounting one of said members and means for adjustably mounting the other of said member, whereby the desired adjustment between said bars can be maintained.

VERNON J. DAVIS. 

